When a child is born or on his birthday, elders, relatives and friends will send silver bracelets, silver locks, silver pendants, etc., which means blessing the child's safety and health. However, in order to meet the appearance and process requirements, some silver jewelry manufacturers will add other metals to the accessories (patching) and solder of silver jewelry, common heavy metal elements such as nickel, cobalt, zinc, lead, copper, rhodium, cadmium and so on. These elements may enter the human body through skin contact, licking and other ways, and continue to accumulate in the human body, causing certain harm to health.